In recent years, compact communication terminal devices such as cellular phones which solely cope with plural radio communication systems using a surface-mounted antenna, such as wireless LAN, GPS, and Bluetooth, have appeared. The frequencies of electric waves used by these radio communication systems are typically different from each other. Plural surface-mounted antennas are provided in one compact mobile terminal device, which cannot make the compact communication terminal device smaller. The study for coping with the plural radio communication systems of different frequencies by one surface-mounted antenna is being advanced.
One of the candidates of such surface-mounted antennas which are now being studied is of a combo antenna type with two power supply electrodes and two radiation electrodes. This has two radiation electrodes on one base surface so that they are not overlapped with each other and supplies power to each of them. Its specific example is described in FIG. 6 of Japanese Patent Application Laid-Open (JP-A) No. 2006-67259.